Egypt releases activist Abdel Fattah

Egyptian activist Alaa Abdel-Fattah has been freed from prison.Image: AAP

A prominent Egyptian activist has been freed after spending five years in jail, his sisters and lawyer say.

Blogger and software engineer Alaa Abdel Fattah was a leading voice amongst the liberal young Egyptians who initially led the 2011 uprising that ended the 30-year rule of autocrat Hosni Mubarak.

Abdel Fattah was jailed for protesting without permission in breach of a 2013 law that rights groups say effectively bans protests. His imprisonment has been seen by activists as an example of what they describe as the worst crackdown on freedoms in Egypt's modern history.

"Alaa got out," his sister Mona Seif wrote on Facebook and Twitter on Friday.

His other sister Sanaa Seif posted a video on Facebook of Abdel Fattah playing with a dog. "Thank God. Alaa Abdel Fattah in his home," his lawyer Khaled Ali wrote in a Facebook post along with a photo of Abdel Fattah with the dog.

Abdel Fattah smiled as he hugged waiting friends upon his release, a video posted on the Facebook page Free Alaa played.

As part of his sentence, Abdel Fattah is required to spend his nights at a police station for the next five years despite his release.

Abdel Fattah is one of many activists jailed since the military overthrew Islamist President Mohamed Morsi in 2013 and cracked down on his Muslim Brotherhood as well as secular pro-democracy activists.

When an Egyptian court upheld a five-year jail sentence against Abdel Fattah in 2017 after he had already served more than three years, prosecutors said he was guilty of organising a protest in November 2013 because he had promoted it on social media.

Rights activists say that President Abdel Fattah al-Sisi has overseen an unprecedented crackdown on dissent in Egypt since he took power in 2014.

At least 60,000 people have been jailed on political grounds, according to a Human Rights Watch estimate.

Sisi has denied holding political prisoners and his backers say the measures were necessary to stabilise Egypt after its 2011 uprising.